Newsletter #98: Social Distancing, Wild Blueberries, and Olive Oil 🧼👏
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Below is our work and a roundup of the various studies and media that captured our attention this week.
This Week’s Research Highlights
🧃 Consuming wild blueberries may improve symptoms of depression.
Researchers randomly assigned 64 healthy 12-17 year olds to receive either a wild blueberry beverage (made from 13 grams of freeze-dried blueberry, containing ~253mg anthocyanins) or a matched placebo beverage (no fruit but containing the same amount of sugars and vitamin C as the experimental beverage). Following the intervention period there were significantly fewer self-reported depression symptoms in participants who were supplemented with the wild blueberry intervention compared to those who received the matched placebo. It is thought that flavonoids may increase blood flow to the dorsolateral prefrontal cortex, a site that is linked to cognitive and emotional regulation. Flavonoids may also mimic the effects of MAO inhibitors, which would also potentially explain their effects on mood.
🔥 Social isolation may be linked to increased systemic inflammation.
In the largest study of its kind, researchers analyzed 30 studies examining the association between inflammation and loneliness and social isolation. They found that social isolation was associated with C-reactive protein and fibrinogen - the latter of which is converted enzymatically into fibrin-based blood clots. There was also a significant association between loneliness and IL-6 in most-adjusted analyses.
🥗 Healthier eating patterns are associated with higher sperm counts, even in young men.
Researchers analyzed lifestyle patterns and sperm samples from 2935 healthy young men, average age 19-20 years. Men in the study who ate a mostly Western diet, characterized by pizza, fries, sweets, sodas, and red and processed meats typically had a lower sperm count - by about 26 million - compared to men who ate far less of these unhealthy foods. Men with the healthiest eating habits had a sperm count 43 million higher than those who ate the fewest amounts of these healthy foods.
📉 Consuming more olive oil is associated with reduced risk of cardiovascular disease, especially when replacing other fat sources.
Researchers analyzed data from 61181 women from the Nurses’ Health Study (1990-2014) and 31797 men from the Health Professionals Follow-up Study (1990-2014) who were free of cancer, heart disease, and stroke at baseline. Diet was assessed using food frequency questionnaires at baseline and then at 4 year intervals. After adjusting for major diet and lifestyle factors, those with higher olive oil intake (>1/2 tablespoon per day or >7 grams per day) had 14% lower risk of cardiovascular disease and 18% lower risk of coronary heart disease. Replacing 5 grams per day of margarine, butter, mayonnaise, or dairy fat with the equivalent amount of olive oil was associated with 5-7% lower risk of total CVD and CHD.
🥱 A single night of sleep loss impairs objective (but not subjective) working memory performance in women.
Researchers recruited 24 young adults and exposed them to two experimental conditions: one night of normal sleep (scheduled between 22:30 and 06:30 hours) versus one night of total sleep loss. Participants were administered a digital working memory test, in which eight‐digit sequences were learned and retrieved in the morning after each condition. After the test, each trial ended with a question regarding how confident participants were of the correctness of their response. Sleep loss was shown to impair objective working memory performance in female participants. However, the self estimations suggested that they were unaware of the impact that the sleep loss had on their performance. This supports prior research suggesting that sleep-deprived individuals often overestimate their capabilities.
Podcasts We Loved This Week
- Peter Hotez: COVID-19 - transmissibility, vaccines, risk reduction, and treatment. Via The Drive with Peter Attia.
- Benhur Lee and Saskia Popescu: Sanitizing, According To Science. Via Science Friday.
- Jonathan Cedernaes: Sleep, Immunity, and Coronavirus. Via Sleep Junkies Podcast.
Products We Are Enjoying
Wireless noise-canceling headphones.
For working at home, potentially in a noisy chaotic environment, I think headphones like this are super helpful for maintaining focus and blocking out distractions. These are inexpensive and reasonably effective, and as an added bonus come in lots of fun colors.
